An analysis of forces for flow around an elliptic cylinder at low Reynolds number has been presented in this work. The finite-volume based open source code OpenFOAM is used for the numerical simulations. pimpleFoam solver is used to solve Navier- Stokes equations for incompressible flow. The combined effects of aspect ratios (AR = 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0), domain sizes (\(D_s\) = 30\(D_h\), 40\(D_h\), 50\(D_h\) and 60\(D_h\)) and Reynolds numbers (Re = 40, 100) on flow fields and various aerodynamic parameters are presented. Here, \(D_h\) represents characteristic length, which is two times the semi-major axis. It is found that at \(Re = 40\), the value of \(C_{D,avg}\) decreases with the increase of aspect ratio. While, at \(Re = 100\), the value of \(C_{D,avg}\) first decreases up to \(AR = 0.5\) and then increases for all domain sizes. The contribution of the pressure and viscous force in the flow is studied in detail for both the Reynolds number. The contribution of pressure in lift force at \(Re = 40\) is found to be one to two times higher than that of viscous force. Whereas, at \(Re = 100\) the contribution of viscous force in producing lift force is insignificant. The value of Strouhal number at \(Re = 100\) is non-decreasing for increase in aspect ratio at a given value of domain size.

在这项工作中，对低雷诺数下椭圆圆柱体周围的流动力进行了分析。基于有限体积的开源代码 OpenFOAM 用于数值模拟。pimpleFoam 求解器用于求解不可压缩流动的 Navier-Stokes 方程。纵横比 ( AR = 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0)、域大小 ( \(D_s\) = 30 \(D_h\) , 40 \(D_h\) , 50 \(D_h\)和 60 \(D_h\) ) 和雷诺数 ( Re = 40, 100) 对流场和各种气动参数进行了介绍。这里，\(D_h\)代表特征长度，是半长轴的两倍。发现在\(Re = 40\)处，\(C_{D,avg}\)的值随着纵横比的增加而减小。而在\(Re = 100\)处，\(C_{D,avg}\)的值首先减小到\(AR = 0.5\)，然后对于所有域大小都会增加。对于雷诺数，详细研究了压力和粘性力在流动中的贡献。在\(Re = 40\)处，压力对升力的贡献被发现是粘性力的一到两倍。而在\(Re = 100\)粘性力对产生升力的贡献是微不足道的。\(Re = 100\)处的 Strouhal 数的值不会随着给定域大小值的纵横比增加而减少。